From fc153c1c58cb8c3bb3b443b4d7dc3211ff5f65fc Mon Sep 17 00:00:00 2001 From: Waiman Long Date: Sun, 5 Dec 2021 22:38:15 -0500 Subject: clocksource: Add a Kconfig option for WATCHDOG_MAX_SKEW A watchdog maximum skew of 100us may still be too small for some systems or archs. It may also be too small when some kernel debug config options are enabled. So add a new Kconfig option CLOCKSOURCE_WATCHDOG_MAX_SKEW_US to allow kernel builders to have more control on the threshold for marking clocksource as unstable. Signed-off-by: Waiman Long Signed-off-by: Paul E. McKenney --- kernel/time/Kconfig | 9 +++++++++ kernel/time/clocksource.c | 8 +++++++- 2 files changed, 16 insertions(+), 1 deletion(-) (limited to 'kernel/time') diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig index 04bfd62f5e5c..27b7868b5c30 100644 --- a/kernel/time/Kconfig +++ b/kernel/time/Kconfig @@ -181,5 +181,14 @@ config HIGH_RES_TIMERS hardware is not capable then this option only increases the size of the kernel image. +config CLOCKSOURCE_WATCHDOG_MAX_SKEW_US + int "Clocksource watchdog maximum allowable skew (in μs)" + depends on CLOCKSOURCE_WATCHDOG + range 50 1000 + default 100 + help + Specify the maximum amount of allowable watchdog skew in + microseconds before reporting the clocksource to be unstable. + endmenu endif diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 1cf73807b450..95d7ca35bdf2 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -107,7 +107,13 @@ static u64 suspend_start; * This delay could be due to SMIs, NMIs, or to VCPU preemptions. Used as * a lower bound for cs->uncertainty_margin values when registering clocks. */ -#define WATCHDOG_MAX_SKEW (100 * NSEC_PER_USEC) +#ifdef CONFIG_CLOCKSOURCE_WATCHDOG_MAX_SKEW_US +#define MAX_SKEW_USEC CONFIG_CLOCKSOURCE_WATCHDOG_MAX_SKEW_US +#else +#define MAX_SKEW_USEC 100 +#endif + +#define WATCHDOG_MAX_SKEW (MAX_SKEW_USEC * NSEC_PER_USEC) #ifdef CONFIG_CLOCKSOURCE_WATCHDOG static void clocksource_watchdog_work(struct work_struct *work); -- cgit v1.2.3